Relationship between left ventricular isovolumic relaxation flow patterns and mitral inflow patterns studied by using vector flow mapping

Vector flow mapping analysis of left ventricular vortex performance in type 2 diabetic patients with early chronic kidney disease

BACKGROUND

Diabetes is the leading cause of chronic kidney disease (CKD) and contributes to an elevated incidence of diastolic dysfunction in the early stages of CKD. Intracardiac vortex is a novel hemodynamic index for perceiving cardiac status. Here, we visualized left ventricular (LV) vortex characteristics using vector flow mapping (VFM) in type 2 diabetic patients with early CKD.

METHODS

This cross-sectional study included 67 controls and 89 type 2 diabetic patients with stages 2-3a CKD. All subjects underwent transthoracic echocardiographic examination. LV anterior vortex during early diastole (E-vortex), atrial contraction (A-vortex) and systole (S-vortex) were assessed using VFM in the apical long-axis view. Its relation to glycemia or LV filling echocardiographic parameters were further analyzed using correlation analysis.

RESULTS

Type 2 diabetic patients with early CKD had a small area (439.94 ± 132.37 mm2 vs. 381.66 ± 136.85 mm2, P = 0.008) and weak circulation (0.0226 ± 0.0079 m2/s vs. 0.0195 ± 0.0070 m2/s, P = 0.013) of E-vortex, but a large area (281.52 ± 137.27 mm2 vs. 514.83 ± 160.33 mm2, P ˂ 0.001) and intense circulation (0.0149 ± 0.0069 m2/s vs. 0.0250 ± 0.0067 m2/s, P < 0.001) of A-vortex compared to controls. CKD patients with poorly controlled hyperglycemia had stronger A-vortex (area: 479.06 ± 146.78 mm2 vs. 559.96 ± 159.27 mm2, P = 0.015; circulation: 0.0221 ± 0.0058 m2/s vs. 0.0275 ± 0.0064 m2/s, P < 0.001) and S-vortex (area: 524.21 ± 165.52 mm2 vs. 607.87 ± 185.33 mm2, P = 0.029; circulation: 0.0174 ± 0.0072 m2/s vs. 0.0213 ± 0.0074 m2/s, P = 0.015), and a longer relative duration of S-vortex (0.7436 ± 0.0772 vs. 0.7845 ± 0.0752, P = 0.013) than those who had well-controlled hyperglycemia. Glycemia, and E/A (a LV filling parameter) were respectively found to had close correlation to the features of A-vortex and S-vortex (all P < 0.05).

CONCLUSIONS

Abnormal LV vortices were detected in type 2 diabetic patients with early CKD using VFM, especially in those who neglected hyperglycemic control. LV vortex might be a promising parameter to slow or halt the hyperglycemia-induced diastolic dysfunction in early CKD.

A comprehensive electrocardiographic analysis for young athletes

ECG-based differences between athletes and sedentary adolescents are a frequently investigated subject in sports medicine. Especially, training-induced ECG variations are common in adult athletes and sustained training often leads to anatomical changes in the heart that can yield abnormalities in ECG. Therefore, ECG screening in athletes is important in diagnosis of cardiac problems of young athletes. The present work investigated the ECG characteristics of young athletes in terms of both gender and sedentary healthy young control group differences. Besides comparison between groups, analysis parameters were also investigated within the groups using correlation analysis. ECG characteristics were extracted using wavelet transform-based adaptive algorithms. Results showed that ECGs of athletes demonstrate differences related to gender and compared to young sedentary. Athletes had significantly lower heart rate; higher QTc, P, and T amplitudes; ST segment; and ST, QT, and RR intervals compared to control group (p < 0.05). Proposed new parameter, namely "scalogram" of each wave, was lower in male athletes compared to other groups (p < 0.05). Negative correlation between T wave amplitude and RR interval could be an indicator of long QT syndrome for male athletes. Furthermore, prolongation of QRS interval in athletes could be the underlying reason of changes in T wave amplitude. Findings of this study can propose indicators for understanding the possible diseases as well as help evaluate the sudden changes in athlete's heart.

Vector flow mapping: A review from theory to practice

BACKGROUND

The interest in intra-cardiac blood flow analysis is rapidly growing, and it has encouraged the development of different non-invasive imaging techniques. Among these, Vector Flow Mapping (VFM), combing Color-Doppler imaging and speckle tracking data, seems to be a promising approach, feasible in adult and children population.

AIM OF THE REVIEW

The aim of this review is to give a historical perspective on the development of VFM method and a summary of the current algorithms and parameters potentially evaluable. Then, we will present the current state-of-the-art of VFM with an overview of clinical studies and applications of this technique.

Evaluation of left ventricular function by vector flow mapping in females with systemic lupus erythematosus

OBJECTIVES

Compare the intraventricular hemodynamics of 60 females with systemic lupus erythematosus (SLE) and 61 healthy female controls, and determine cardiac function changes using vector flow mapping (VFM).

METHODS

To determine the effect of pulmonary artery pressure changes on left ventricular function, SLE patients were divided into a normal pulmonary artery pressure group (S1, n=24) and an elevated pulmonary artery pressure group (S2, n=36). The energy loss (EL) at each segment of the left ventricular chamber (total, basal, middle, and apical segments) during each period of the cardiac cycle (isovolumic contraction, rapid ejection, rapid filling, reduced filling, atrial contraction) was determined.

RESULTS

The S1 group had significantly more vortices than the control group during the rapid ejection, rapid filling, and atrial contraction periods (p<0.01), and the maximum vortex areas in the S1 and S2 groups were smaller than in the control group during rapid filling and atrial contraction periods (p<0.05). Compared with the control group, the S2 group had greater EL during the systole and diastole periods (p<0.01). EL in the S1 group was significantly greater than in the control group during systole (p<0.01). During the rapid filling period, the EL was positively correlated with septal E' (r=0.784, p<0.01), and during the atrial contraction period, EL was positively correlated with septal E/e' (r=0.812, p<0.01) and A (r=0.715, p<0.01).

CONCLUSION

VFM of patients with SLE can comprehensively, rapidly, and efficiently evaluate changes of myocardial mechanics and intracardiac hemodynamics and provide quantitative analysis of complex intracardiac blood flow. Key points • Vector flow mapping (VFM) is a new non-invasive ultrasound technique that evaluates changes of myocardial mechanics and intracardiac hemodynamics, and provides quantitative analysis of complex intracardiac blood flow. • This study showed that vortex and energy loss may provide more sensitive detection of cardiac dysfunction than conventional echocardiographic indexes in patients with systemic lupus erythematosus.

Characterization of left ventricular cavity flow, wall stress and energy loss by color doppler vector flow mapping in children and adolescents with cardiomyopathy

Background

Vector flow mapping is an emerging echocardiographic method allowing for investigation of intracardiac blood flow mechanics, wall shear stress (WSS), and energy loss (EL). We hypothesized that alterations in EL and WSS will differ among subjects with hypertrophic (HCM), dilated (DCM) cardiomyopathy, and normal controls.

Methods

Echocardiograms were prospectively performed with the ProSound F75CV (Hitachi HealthCare., Tokyo, Japan) on all subjects. 2D color Doppler cine loop images were obtained from apical 5 and the apical long axis views and stored digitally. Measurements were averaged over three cardiac cycles using VFM software to derive flow patterns, WSS, and EL. Standard left ventricular (LV) systolic and diastolic functional parameters were also obtained.

Results

A total of 85 subjects, 22 with HCM (age 18 ± 9 yrs.), 18 DCM (age 18 ± 9 yrs.), and 45 age and gender matched controls were included in the study. Diastolic wall shear stress was found significantly different in HCM (0.004 ± 0.185 N/m²) compared with DCM (0.397 ± 0.301 N/m², P < 0.001), and controls (0.175 ± 0.255 N/m², P = 0.027). Furthermore, indexed systolic EL was found to be significantly elevated in HCM (13.91 ± 13.17 mW/m²/m³) compared with DCM (8.17 ± 9.77 mW/m²/m³, P < 0.001), but not controls (6.45 ± 7.47 mW/m²/m³).

Conclusion

Differences in abnormal ventricular mechanics observed in HCM and DCM are reflected in both EL and WSS, and are suggestive that changes in energetic parameters may represent novel indices of ventricular dysfunction.